I recently had a leak in the HH zones and found that there was a loose hose on the rear of the unit
. We have a 36' FDTS so I was able to remove the blocking around the inverter/charger and get to the rear of the unit by crawling through from the passengers side. While I had it apart I took a picture thinking someone might want to know what is back there.
Lower right is the circulator pump for the engine preheat.
Lower center is the mixer valve for domestic hot water.
Upper right and left are the zone connections (that is where the leak was).
Upper center is the engine preheat return.
WRV and a loose connection who would have imagined